[1/3] bcm2835_gpio: Add support for pinmux

Message ID 20180116134638.3879-2-agraf@suse.de
State New
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Series
  • Rpi: Add support for second sd host controller
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Commit Message

Alexander Graf Jan. 16, 2018, 1:46 p.m.
On the bcm2835 the GPIO IP block is responsible to control pin muxing
of the configurable pins on the chip.

This adds a simple helper function that allows a device driver to set
pin muxing according to device tree configuration on those devices.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/arm/mach-bcm283x/include/mach/gpio.h |  1 +
 drivers/gpio/bcm2835_gpio.c               | 40 +++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

Comments

Amit Tomer Jan. 17, 2018, 9:26 a.m. | #1
Hi,

> +       val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
> +       val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
> +       val |= (func << BCM2835_GPIO_FSEL_SHIFT(gpio));
> +       writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);

Can clrsetbits_le32 be used here ?

Thanks
-Amit
Simon Glass Jan. 17, 2018, 8:06 p.m. | #2
Hi Alex,

On 16 January 2018 at 05:46, Alexander Graf <agraf@suse.de> wrote:
> On the bcm2835 the GPIO IP block is responsible to control pin muxing
> of the configurable pins on the chip.
>
> This adds a simple helper function that allows a device driver to set
> pin muxing according to device tree configuration on those devices.
>
> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  arch/arm/mach-bcm283x/include/mach/gpio.h |  1 +
>  drivers/gpio/bcm2835_gpio.c               | 40 +++++++++++++++++++++++++++++++
>  2 files changed, 41 insertions(+)
>
> diff --git a/arch/arm/mach-bcm283x/include/mach/gpio.h b/arch/arm/mach-bcm283x/include/mach/gpio.h
> index daaee52f81..751594d09f 100644
> --- a/arch/arm/mach-bcm283x/include/mach/gpio.h
> +++ b/arch/arm/mach-bcm283x/include/mach/gpio.h
> @@ -62,5 +62,6 @@ struct bcm2835_gpio_platdata {
>  };
>
>  int bcm2835_gpio_get_func_id(struct udevice *dev, unsigned gpio);
> +void bcm2835_gpio_set_pinmux(struct udevice *dev, int handle);
>
>  #endif /* _BCM2835_GPIO_H_ */
> diff --git a/drivers/gpio/bcm2835_gpio.c b/drivers/gpio/bcm2835_gpio.c
> index beaa21853a..209cbed9e6 100644
> --- a/drivers/gpio/bcm2835_gpio.c
> +++ b/drivers/gpio/bcm2835_gpio.c
> @@ -83,6 +83,46 @@ int bcm2835_gpio_get_func_id(struct udevice *dev, unsigned gpio)
>         return (val >> BCM2835_GPIO_FSEL_SHIFT(gpio) & BCM2835_GPIO_FSEL_MASK);
>  }
>
> +static void bcm2835_gpio_set_func_id(struct udevice *dev, unsigned gpio, int func)
> +{
> +       struct bcm2835_gpios *gpios = dev_get_priv(dev);
> +       u32 val;
> +
> +       val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
> +       val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
> +       val |= (func << BCM2835_GPIO_FSEL_SHIFT(gpio));
> +       writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
> +}
> +
> +void bcm2835_gpio_set_pinmux(struct udevice *dev, int handle)
> +{
> +       int node = fdt_node_offset_by_phandle(gd->fdt_blob, handle);
> +       u32 pins[16];
> +       int len;
> +       u32 func;
> +       int i;
> +
> +       if (!node)
> +               goto err;
> +
> +       func = fdtdec_get_int(gd->fdt_blob, node, "brcm,function", -1);
> +       if (func <= 0)
> +               goto err;
> +
> +       len = fdtdec_get_int_array_count(gd->fdt_blob, node, "brcm,pins", pins,
> +                                        ARRAY_SIZE(pins));
> +       if (len <= 0)
> +               goto err;
> +
> +       for (i = 0; i < len; i++)
> +               bcm2835_gpio_set_func_id(dev, pins[i], func);
> +
> +       return;
> +err:
> +       printf("Failed to pinmux phandle 0x%x\n", handle);
> +       return;
> +}

This should use livetree functions and I'm pretty sure it should go in
a pinctrl driver, not GPIO.

> +
>  static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset)
>  {
>         int funcid = bcm2835_gpio_get_func_id(dev, offset);
> --
> 2.12.3
>

Regards,
Simon
Alexander Graf Jan. 17, 2018, 10 p.m. | #3
On 17.01.18 10:26, Amit Tomer wrote:
> Hi,
> 
>> +       val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
>> +       val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
>> +       val |= (func << BCM2835_GPIO_FSEL_SHIFT(gpio));
>> +       writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
> 
> Can clrsetbits_le32 be used here ?

Yeah, thanks for the suggestion!

Alex

Patch

diff --git a/arch/arm/mach-bcm283x/include/mach/gpio.h b/arch/arm/mach-bcm283x/include/mach/gpio.h
index daaee52f81..751594d09f 100644
--- a/arch/arm/mach-bcm283x/include/mach/gpio.h
+++ b/arch/arm/mach-bcm283x/include/mach/gpio.h
@@ -62,5 +62,6 @@  struct bcm2835_gpio_platdata {
 };
 
 int bcm2835_gpio_get_func_id(struct udevice *dev, unsigned gpio);
+void bcm2835_gpio_set_pinmux(struct udevice *dev, int handle);
 
 #endif /* _BCM2835_GPIO_H_ */
diff --git a/drivers/gpio/bcm2835_gpio.c b/drivers/gpio/bcm2835_gpio.c
index beaa21853a..209cbed9e6 100644
--- a/drivers/gpio/bcm2835_gpio.c
+++ b/drivers/gpio/bcm2835_gpio.c
@@ -83,6 +83,46 @@  int bcm2835_gpio_get_func_id(struct udevice *dev, unsigned gpio)
 	return (val >> BCM2835_GPIO_FSEL_SHIFT(gpio) & BCM2835_GPIO_FSEL_MASK);
 }
 
+static void bcm2835_gpio_set_func_id(struct udevice *dev, unsigned gpio, int func)
+{
+	struct bcm2835_gpios *gpios = dev_get_priv(dev);
+	u32 val;
+
+	val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
+	val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
+	val |= (func << BCM2835_GPIO_FSEL_SHIFT(gpio));
+	writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
+}
+
+void bcm2835_gpio_set_pinmux(struct udevice *dev, int handle)
+{
+	int node = fdt_node_offset_by_phandle(gd->fdt_blob, handle);
+	u32 pins[16];
+	int len;
+	u32 func;
+	int i;
+
+	if (!node)
+		goto err;
+
+	func = fdtdec_get_int(gd->fdt_blob, node, "brcm,function", -1);
+	if (func <= 0)
+		goto err;
+
+	len = fdtdec_get_int_array_count(gd->fdt_blob, node, "brcm,pins", pins,
+					 ARRAY_SIZE(pins));
+	if (len <= 0)
+		goto err;
+
+	for (i = 0; i < len; i++)
+		bcm2835_gpio_set_func_id(dev, pins[i], func);
+
+	return;
+err:
+	printf("Failed to pinmux phandle 0x%x\n", handle);
+	return;
+}
+
 static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset)
 {
 	int funcid = bcm2835_gpio_get_func_id(dev, offset);